Airworthiness Directive · Amendment 39-19603 · Tail rotor gearbox
Airbus Helicopters Deutschland GmbH Helicopters
This AD applies to Airbus Helicopters Deutschland GmbH Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, MBB-BK 117 C-1, and MBB-BK 117 C-2 helicopters, certificated in any category.
We are adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model MBB-BK 117 A-1, MBB-BK 117A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, MBB-BK 117 C-1, and MBB-BK 117 C-2 helicopters. This AD requires repetitive inspections of the tail rotor (T/R) gearbox housing. This AD was prompted by a report that a crack was found in a T/R gearbox housing. The actions of this AD are intended to correct an unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 100 hours time-in-service (TIS) and thereafter at intervals not to exceed 100 hours TIS, clean and visually inspect the T/R gearbox housing for a crack in the area depicted in Figure 1 of Airbus Helicopters Alert Service Bulletin (ASB) MBB-BK117-30A-119, Revision 0, dated May 24, 2016, or ASB MBB-BK117 C-2-65A-007, Revision 0, dated May 24, 2016, as applicable to your model helicopter. If there is a crack, replace the T/R gearbox before further flight.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
